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WanderNerd

Route Reliability

Buffalo → Denver

BUFDEN · 1,359 miles · Buffalo Niagara International Airport to Denver International Airport

87
Pretty Reliable
WanderNerd Reliability Score
81%
Arrive within 15 minutes
5 min
Average arrival delay
0.3%
Cancelled
614
Flights in the data

Data through May 2026.

Who flies it best

Ranked by on-time arrivals. Historical results, not predictions.

  1. 1.United Airlines86%293 flights
  2. 2.Southwest Airlines80%262 flights

Not enough history to rank: Frontier Airlines (59 flights). We rank airlines only after 100 flights on the route.

What the data says

Morning-you made the right choice.

BUF–DEN flights departing between 3–6 AM arrived on time 89% of the time, versus 55% between 3–6 PM.

Wednesdays have been rough.

BUF–DEN flights arrived on time 94% of the time on Thursdays and just 77% on Wednesdays. That gap is worth planning around.

United Airlines has a slight edge here.

United Airlines arrived on time 86% of the time on this route; Southwest Airlines managed 80%.

It basically never cancels.

Out of 614 scheduled flights, only 0.3% were cancelled.

Flights on this route

The breakdown

On-time by weekday
  • Mon78%(96 flights)
  • Tue79%(67 flights)
  • Wed77%(73 flights)
  • Thu94%(72 flights)
  • Fri79%(97 flights)
  • Sat77%(110 flights)
  • Sun85%(96 flights)
On-time by departure window
  • 3–6 AM89%(45 flights)
  • 6–9 AM87%(362 flights)
  • 9 AM–12 PM80%(65 flights)
  • 12–3 PM86%(43 flights)
  • 3–6 PM55%(91 flights)
  • 6–9 PM(5 flights)
On-time trend by month
81%
May

Jun 91% → May 81% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202591%77
July 202582%83
August 202582%81
September 202577%77
October 202587%70
November 202581%52
December 202568%19
January 202664%14
February 202672%36
March 202676%33
April 202685%33
May 202681%36

Based on 614 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.